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Could isolation transformers prevent electrocution on LU tracks?
On Sep 22, 12:41*pm, Roy Badami wrote:
On 21/09/10 18:15, The Gardener wrote: On the Southern, both running rails are used for traction return. Trackcircuits are AC as a result; historically 50 Hz but moderntrack circuits (known as TI for Traction Immune) use higher frequencies (I believe in the range 1.1-1.3 kHz) to avoid the risk of harmonics in the return current giving a false clear indication. I thought moderntrackcircuits transmit a digital code so as to completely eliminate the risk of traction systems generating the appropriate frequency? * * *-roy You're thinking of the HVI (High Voltage Impulse) type. These are used where there is a risk of low wheel-rail adhesion causing the train to "disappear" from the system. TI types are generally more common. HTH. |
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